Method for emulsion dispersing and apparatus for the same

ABSTRACT

A method for emulsion dispersing which consists of mixing the liquids to be emulsion dispersed together with a proper emulsifying agent, pressurizing the mixture through a pump and ejecting the mixture from the pump through at least three orifices arranged in series. The spacing of the orifices arranged in series is such that it takes between 1/50,000 to 1/100 seconds for the mixture ejected from one orifice to reach the next orifice.

United States Patent Mimura'et al.

[ 51 Mar. 14, 1972 METHOD FOR EMULSION DISPERSING AND APPARATUS FOR THE SAME lnventors: Norihisa Mimura; Hiroshi Chlkamasa; Kotaro Aso; Takashi Sato, all of Kanagawa, Japan Assignee: Fuji Photo Film Co., Ashigara-Kamagun,

Kanagawa, Japan Filed: Mar. 12, 1970 Appl. No.: 18,994

Foreign Application Priority Data Mar. 17, 1969 Japan ..44/20262 US. Cl ..259/4, 259/95 Int. Cl. ...B0lf 11/00, BOlf 5/10 Field of Search ..259/95-98, 4;

[56] References Cited UNITED STATES PATENTS 3,526,391 9/1970 Church ...259/4 3,169,013 2/1965 Jones ..259/4 FOREIGN PATENTS OR APPLlCATlON S 330,151 12/1920 Germany ..138/44 Primary Examiner-William 1. Price Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak 571 Ahsrimcr A method for emulsion dispersing which consists of mixing the liquids to be emulsion dispersed together with a proper emulsifying agent, pressurizing the mixture through a pump and ejecting the mixture from the pump through at least three ori fices arranged in series. The spacing of the orifices arranged in series is such that it takes between l/50,000 to l/ 100 seconds for the mixture ejected from one orifice to reach the next orifree.

6 Claims, 2 Drawing Figures PATENTEDMAR 14 m2 INVENTORS. NORIHISA MIMURA HIROSHI CHIKAMASA KOTARO ASO BY TAKASHI SATO M); I ATTORNEYS.

METHOD FOR EMULSION DISPERSING AND APPARATUS FOR THE SAME BACKGROUND OF THE INVENTION The present invention relates to a method for emulsion dispersing one liquid into another liquid which is insoluble with the former, and to an apparatus for carrying out the above method. The present invention relates particularly to a method and apparatus for emulsion dispersing an oil solution of a coupler into a gelatin liquid as in the production of photosensitive material where the production of a super-fine grain emulsion dispersed liquid is desired.

In the prior art the methods most often used to produce a fine grain emulsion dispersed liquid were colloid mills, homogenizers, and ultrasonic wave emulsifying devices..In colloid mills, however, the heat generation involved in the process was often so high that the liquid to be emulsion dispersed was destroyed. The disadvantage of conventional homogenizers or ultrasonic emulsifying devices is that they do not produce an emulsion liquid with a grain size as fine as could be desired.

SUMMARY OF THE INVENTION The object of the present invention is to provide a method and apparatus for producing an emulsion liquid of grain size much finer that as heretofore been produced by conventional processes.

In accordance with the present invention there is provided a method and apparatus in which two liquids to be emulsion dispersed are mixed with each other with the proper emulsifying agent, pressurized by a pump and ejected through a series of small orifices consisting of at least three orifices in the series. The spacing of the orifices arranged in series is made such that it takes between l/50,000 of a second to H100 of a second for the ejected liquid to reach the next orifice after ejection from a preceding orifice.

Other objects and advantages will be made apparent from the following description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional side elevation view of an embodiment of the apparatus in accordance with the present invention.

FIG. 2 is a cross-sectional side elevational view of another embodiment of the apparatus in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a basic embodiment of the apparatus in accordance with the present invention in which the pressure pump 3 is connected with orifices 4', 4 up to 4n arranged in series. The invention requires that at least three orifices are connected to the outlet side of the pressure pump 3 in such a manner that the output of pressure pump 3 must pass sequen-v tially through each of the orifices. The arrow marked 1 indicates the inlet of the dispersed mixture into the pressure pump 3. The arrow marked'2 indicates the outlet of the emulsion dispersed liquid. The spacing between adjacent orifices indicated by the letter L in FIG. 1 is so set that at a constant flow rate from pressure pump 3 the ejected liquid requires between l/50,000 to l/lOO seconds to travel from each orifice to the following orifice.

FIG. 2 shows another embodiment of the apparatus in accordance with the present invention in which vibrative auxiliary blades 5, 5" to 5n are incorporated just downstream of orifices 4', 4" to 4n, respectively.

In operation the liquids to be emulsion dispersed and the proper emulsifying agent are mixed and compressed by pump 3 and then ejected through orifices 4' and 4" to 4n. The output of the last orifice in the series, designated as 4n can be recycled to the input of pump 3 if it is desired to make the grain size of the emulsion dispersed liquid more uniform. FIG. 1 shows recycling pipe 6 for recycling the flow;

The pressure at the outlet side of the pressure pump 3 is selected according to the desired diameter of emulsion grains. Generally it is selected so that the average pressure loss per orifice is in the range of 210 lbs. per sq. inch. The pump 3 obviously, must be capable of an output pressure greater than 210 lbs. per sq. inch times the total number of orifices in the series. The shape of the orifice cross section is not limited to a circle, but may be of any shape if the orificehas proper crosssectional area to provide the above pressure loss. Generally, a circular or oval shape of orifice is used, but most preferably, cross section of the orifice shouldbe like the section of the equiconvex lens.

The overall size of the apparatus depends-upon the volumerate of emulsion dispersed liquid desired, andthe total number of orifices used is. determined by the grain size of the emulsion liquid desired. Similarly, the number of times, if any, the emulsion dispersed liquid output at outlet 2 is recycled to the input I of pressure pump 3 depends upon the uniformity of grain size desired.

When auxiliary blades 5', 5 etc., are incorporated downstream of orifices 4, 4" etc., as shown in FIG. 2, the operation of the apparas in emulsifying the liquid mixture is made even more efficient as the turbulence introduced by the blades aids the turbulence at the orifices in distorting and shearing larger into smaller grains. The blades which are designed to intersect the central flow fromeach orifice are set into vibration by liquid ejected from the orifices and thereafter act as choppers as well as shearers for liquid subsequently being ejected from these orifices.

As an example of the method and apparatus described above applied to a specific emulsion, a photosensitive emulsion was made of oil, ester, a coupler, and other ingredients into a gelatin and surface activator solution; The emulsion was mixed and pressurized by pump 3 to a pressure in excess of 750 lbs. per sq. inch and the emulsion was then passed through a series containing three orifices with'a pressure loss of approximately 240 lbs. per sq. inch at each orifice wherein the orifices were arranged such that the liquid ejected from the one orifice took l/l0,000 second to reach the next orifice. The product of this apparatus was an emulsion containing grain sizes of less than 0.04 microns in average diameter and this average diameter was fairly uniform without the requirement of the recycling. It is further noted that the color film transparency made from this (photosensitive) emulsion was of very high quality.

What is claimed is:

l. A method for emulsion dispersing including the steps of mixing the solutions to be emulsion dispersed with-a proper emulsifying assistant, pressurizing this mixture, ejecting the pressurized mixture through a plurality of orifices arranged in an axially aligned, spaced series, mechanically emulsifying the effluent from each orifice before it reaches the following orifice and arranging the flow rate of the mixture and the spacing between said orifices to make the solution ejected from one orifice reach the next orifice in 1/50,000 to l seconds.

2. A method for emulsion dispersing as claimed inclaim 1 further comprising the step of re-pressurizing and re-ejecting the output of the last orifice in the series.

3. A method for emulsion dispersing as defined in claim 1 wherein the flow rate and mixture pressure are so set as to cause a pressure drop of about 210 psi. across each orifice.

4. An apparatus for emulsion dispersing a mixture of liquids which includes a pump for mixingand pressurizing said mixture and arranged downstream of the output of said pump, a plurality of orifices arranged in a axially aligned, spaced series with the distance between each pair of orifices for a given flow rate of liquids within the apparatus being such that the ejected liquid mixture travels the distance between said orifices in l/50,000 to 1/100 of a second, and a vibratory blade for mechanically emulsifying said mixture I being positioned downstream of each nozzle and in axial alignmenttherewith.

5. An apparatus for emulsion dispersing as claimed in claim 4 wherein more than three orifices are provided.

6. An apparatus for emulsion dispersing as defined in claim 4 wherein means is provided to connect the output of the last orifice in said series of orifices to the intake of said pump whereby the emulsion dispersing process can be repeated. 

2. A method for emulsion dispersing as claimed in claim 1 further comprising the step of re-pressurizing and re-ejecting the output of the last orifice in the series.
 3. A method for emulsion dispersing as defined in claim 1 wherein the flow rate and mixture pressure are so set as to cause a pressure drop of about 210 p.s.i. across each orifice.
 4. An apparatus for emulsion dispersing a mixture of liquids which includes a pump for mixing and pressurizing said mixture and arranged downstream of the output of said pump, a plurality of orifices arranged in an axially aligned, spaced series with the distance between each pair of orifices for a given flow rate of liquids within the apparatus being such that the ejected liquid mixture travels the distance between said orifices in 1/50,000 to 1/100 of a second, and a vibratory blade for mechanically emulsifying said mixture being positioned downstream of each nozzle and in axial alignment therewith.
 5. An apparatus for emulsion dispersing as claimed in claim 4 wherein more than three orifices are provided.
 6. An apparatus for emulsion dispersing as defined in claim 4 wherein means is provided to connect the output of the last orifice in said series of orifices to the intake of said pump whereby the emulsion dispersing process can be repeated. 